Vice-President Elias Jaua said Mr Chavez had been in close contact with officials in an effort to "continue driving the national plans forward".

Mr Chavez's unexpectedly long absence from the country has prompted debate on whether he should delegate executive power to the vice-president.

Venezuelan officials have said he underwent emergency surgery on 10 June for a pelvic abscess, but there has been speculation in the Venezuelan and foreign press that the president's condition could be more serious.

He had been widely expected to be back in time to host the CELAC summit which also coincides with Venezuela's bicentennial celebrations.

President Chavez is one of the driving forces behind CELAC, seen as an alternative to the Organization of American States (OAS). Unlike the OAS, CELAC excludes the US and Canada.

The BBC's Sarah Grainger in Caracas said President Chavez wants to see greater co-operation between Latin American nations and less US influence in the region.